"Unit 7 of Rajasthan Atomic Power Project 7&8 … achieved a major milestone of successful completion of Hot Conditioning of the Primary Heat Transport (PHT) system on November 30, 2023," NPCIL said. "Hot conditioning is a commissioning process to develop an adherent protective layer of magnetite in inner surfaces of carbon steel piping of the PHT system. Hot conditioning was achieved by circulating light water of controlled chemistry through the PHT system, maintaining a temperature around 256°C and pressure of about 100 kg/cm2."
This is a prelude to "further commissioning activities" including fuel loading and first criticality, the company added.
Two 700 MWe PHWRs are under construction at the plant at Rawatbhata in Rajasthan, where five PHWR units are currently in operation (one unit, the 90 MWe (net) Rajasthan 1, was permanently closed in 2004 after more than 30 years in operation). Construction of units 7 and 8 began in 2011 and once they are completed, the installed capacity at the site will increase to 2580 MW, NPCIL said.
The first Indian-designed 700 MWe PHWR, Kakrapar 3, began commercial operation earlier this year and fuel loading began at the second, Kakrapar 4, in October.
In addition, four Russian-supplied 1000 MWe VVER pressurised water reactors are currently under construction at Kudankulam: units 3 and 4, under construction since 2017, and units 5 and 6, under construction since 2021. A 500 MWe prototype fast breeder reactor is also under construction at Kalpakkam.
